What is the BDN and what must it contain?

Bunker Delivery Note. Mandatory under MARPOL Annex VI Reg. 18. Must record: name and address of supplier; receiving ship name and IMO; port; date of commencement; product name and density at 15 °C; sulphur content (declared); volume in litres at 15 °C; mass in metric tonnes; supplier signature. Retained on board for 3 years. The MARPOL representative sample is sealed and signed jointly by ship and supplier; retained 12 months.

How is the MARPOL sample drawn?

MEPC.1/Circ.864 sets the drip-sampling procedure. A continuous drip sampler at the ship's manifold collects a single representative sample throughout the bunkering. After the operation: agitate, fill four sample bottles (one for ship retention, one for supplier, one for joint MARPOL sample, one spare), label, seal with both supplier and ship seals, both parties sign the seal labels. The joint MARPOL sample is the legal evidence in any sulphur-cap or quality dispute.

What is ROB and why does it matter?

Remaining On Board — the volume in your bunker tanks before bunkering starts. Read by sounding all bunker tanks, applying tank tables, and correcting to a reference temperature. Compare against the BDN's stated delivered volume + (post-bunker ROB - pre-bunker ROB). Discrepancies (typically the supplier's claimed volume vs the actual volume increase) are the most common short-bunker dispute and drive a Letter of Protest.

When do I issue a Letter of Protest?

Whenever there is a discrepancy you cannot resolve at the manifold: short delivery, off-spec density (compared to BDN claim), stoppage of supply, refusal to draw a joint sample, water content above ISO 8217 limits suspected. Issue the Letter of Protest in writing, signed, and have the supplier sign it as 'received' (not 'agreed'). Notify the company / DPA immediately. The MARPOL sample is the eventual evidence; the LOP preserves the record.

Bunker delivery procedure

MARPOL Annex VI Reg. 18 governs bunker fuel quality and the documentation that travels with every delivery. The BDN is the legal record; the MARPOL sample is the evidence; the ROB calculation is the audit. ISGOTT (6th edition) supplies the safety checklist for the manifold operation. Done correctly the procedure takes time but produces an auditable bunker file that protects the operator and the master against quality and short-delivery disputes.

Pre-bunker checklist (ISGOTT)

1. Bunker plan — quantity, grade, supplier, manifold connection, distribution to receiving tanks. Signed by Chief Engineer.
2. Receiving tanks gauged — pre-bunker ROB measured with the ullage tape; sounding records signed and dated. All tanks checked for water (water finder paste).
3. Permit to work issued for the bunkering job; risk assessment for fuel-spill containment, hot-work prohibition, smoking ban.
4. Pre-bunker meeting with bunker barge crew: communication channel (VHF), max delivery rate, manifold connection, ESD signal, agreed stop signal, sample procedure, BDN handover.
5. Spill containment in place: scuppers plugged, drip trays under all flange connections, oil-spill response equipment ready.
6. SOPEP / vessel response plan at hand. Notification list verified (port authority emergency contact).

During delivery

· Continuous drip-sample at the manifold throughout the operation. Confirm the sampler is in correct alignment before start.
· Watch the rate — start slow, ramp once the line is full, monitor manifold pressure. Keep within the agreed maximum rate.
· Trim and stability — monitor draft and any list developing. Stop if ship's stability is at risk.
· Tank topping — slow rate as each receiving tank approaches 90% capacity; final fill at minimum rate.
· Pollution watch at the manifold and overboard scuppers throughout. Anyone seeing a leak hits the ESD button immediately.

After delivery

1. Final ROB measured in each receiving tank and the day tank.
2. Calculate volume delivered: (post-ROB - pre-ROB) corrected to 15 °C. Compare against BDN.
3. Joint sample sealing: agitate the drip sample; fill four bottles; seal with supplier and ship seals; both parties sign the seal labels.
4. BDN signing — sign 'as received' or with a Letter of Protest if there is a discrepancy.
5. Ship retains: 1 sample × 12 months minimum; BDN × 3 years minimum.
6. Quality test by an independent lab (Veritas, FOBAS, DNV Petroleum Services) — typical 5-7 days result.
7. If lab returns off-spec result, the joint MARPOL sample is the authoritative evidence; the Master and DPA invoke the supplier dispute under the bunker contract terms.

Common short-bunker traps

· Cappuccino effect — air entrained in the fuel making the meter read more than was actually delivered. Protective measures: settled fuel; inline thermometer.
· Density misstatement — supplier's claimed density on BDN higher than actual; mass is inflated. Caught by lab analysis of the MARPOL sample.
· Off-spec sulphur — supplier delivers higher-sulphur grade than ordered; vessel risks MARPOL Annex VI breach. Caught by the MARPOL sample sulphur test.
· Water content — water above ISO 8217 limits causes purifier overload; particularly problematic on residual grades.
· Mid-bunker line transfers — supplier switches barges or lines mid-bunker without notice; contamination risk.

Sources: MARPOL Annex VI Reg. 18 + Reg. 18.8.1 (representative sample); MEPC.1/Circ.864 (sampling procedure); ISGOTT 6th edition (OCIMF/ICS/IAPH 2020); ISO 8217:2017 (marine fuels). See also ISO 8217, BDN, bunker sample, fuel consumption calculator.

Last verified 4 months ago